U.S. patent application number 12/739911 was filed with the patent office on 2010-09-30 for mobile station apparatus, base station apparatus, communication method and communication system.
This patent application is currently assigned to SHARP KABUSHIKI KAISHA. Invention is credited to Tatsushi Aiba, Yosuke Akimoto, Seiji Sato, Shohei Yamada.
Application Number | 20100248733 12/739911 |
Document ID | / |
Family ID | 41090874 |
Filed Date | 2010-09-30 |
United States Patent
Application |
20100248733 |
Kind Code |
A1 |
Sato; Seiji ; et
al. |
September 30, 2010 |
MOBILE STATION APPARATUS, BASE STATION APPARATUS, COMMUNICATION
METHOD AND COMMUNICATION SYSTEM
Abstract
In the case that periodical transmission of transmission signal
number-of-sequence quality indicative signal cannot be performed,
the number of transmission signal sequences is clarified in
association with reception quality information that is generated
immediately after the case, and the base station apparatus performs
appropriate communication resource allocation. A mobile station
apparatus has a feedback information control section 65 that
generates feedback information including reception quality
information, transmission signal preprocessing information and
transmission signal number-of-sequence information, and a radio
transmission section 51 that periodically transmits the generated
feedback information to the base station apparatus, where when the
radio transmission section 51 does not transmit the transmission
signal number-of-sequence information with communication resources
periodically allocated from the base station apparatus so as to
transmit the transmission signal number-of-sequence information,
the radio transmission section 51 transmits the transmission signal
number-of-sequence information to the base station apparatus with
communication resources enabling transmission of the feedback
information allocated from the base station apparatus subsequently
to the communication resources.
Inventors: |
Sato; Seiji; (Osaka, JP)
; Akimoto; Yosuke; (Osaka, JP) ; Yamada;
Shohei; (Osaka, JP) ; Aiba; Tatsushi; (Osaka,
JP) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Assignee: |
SHARP KABUSHIKI KAISHA
Osaka-shi, Osaka
JP
|
Family ID: |
41090874 |
Appl. No.: |
12/739911 |
Filed: |
March 13, 2009 |
PCT Filed: |
March 13, 2009 |
PCT NO: |
PCT/JP2009/054926 |
371 Date: |
April 26, 2010 |
Current U.S.
Class: |
455/452.1 ;
455/561; 455/67.13 |
Current CPC
Class: |
H04B 17/309 20150115;
H04L 1/0027 20130101; H04B 17/24 20150115; H04L 1/0026 20130101;
H04L 1/20 20130101 |
Class at
Publication: |
455/452.1 ;
455/67.13; 455/561 |
International
Class: |
H04W 72/08 20090101
H04W072/08; H04B 17/00 20060101 H04B017/00; H04M 1/00 20060101
H04M001/00; H04W 88/02 20090101 H04W088/02 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 19, 2008 |
JP |
2008-072465 |
Claims
1. A mobile communication system in which a mobile station
apparatus periodically transmits transmission signal
number-of-sequence information and reception quality information
calculated based on the transmission signal number-of-sequence
information to a base station apparatus, wherein the mobile station
apparatus calculates the reception quality information based on the
predetermined number of transmission signal sequences when the
transmission signal number-of-sequence information is not
transmitted to the base station apparatus, and the base station
apparatus processes the reception quality information based on the
predetermined number of transmission signal sequences when the
transmission signal number-of-sequence information is not
transmitted.
2. The mobile communication system according to claim 1, wherein
the predetermined number of transmission signal sequences is the
minimum number of transmission signal sequences.
3. The mobile communication system according to claim 1, wherein
the predetermined number of transmission signal sequences is the
maximum number of transmission signal sequences.
4. A mobile communication system in which a mobile station
apparatus periodically transmits transmission signal
number-of-sequence information and transmission signal
preprocessing information calculated based on the transmission
signal number-of-sequence information to a base station apparatus,
wherein the mobile station apparatus calculates the transmission
signal preprocessing information based on the predetermined number
of transmission signal sequences when the transmission signal
number-of-sequence information is not transmitted to the base
station apparatus, and the base station apparatus processes the
transmission signal preprocessing information based on the
predetermined number of transmission signal sequences when the
transmission signal number-of-sequence information is not
transmitted.
5. The mobile communication system according to claim 4, wherein
the predetermined number of transmission signal sequences is the
minimum number of transmission signal sequences.
6. The mobile communication system according to claim 4, wherein
the predetermined number of transmission signal sequences is the
maximum number of transmission signal sequences.
7. A base station apparatus for periodically receiving transmission
signal number-of-sequence information and reception quality
information calculated in a mobile station apparatus based on the
transmission signal number-of-sequence information from the mobile
station apparatus, comprising: a section that processes the
reception quality information based on the predetermined number of
transmission signal sequences when the transmission signal
number-of-sequence information is not transmitted.
8. The base station apparatus according to claim 7, wherein the
predetermined number of transmission signal sequences is the
minimum number of transmission signal sequences.
9. The base station apparatus according to claim 7, wherein the
predetermined number of transmission signal sequences is the
maximum number of transmission signal sequences.
10. A base station apparatus for periodically receiving
transmission signal number-of-sequence information and transmission
signal preprocessing information that is calculated in a mobile
station apparatus based on the transmission signal
number-of-sequence information from the mobile station apparatus,
comprising: a section that processes the transmission signal
preprocessing information based on the predetermined number of
transmission signal sequences when the transmission signal
number-of-sequence information is not transmitted.
11. The base station apparatus according to claim 10, wherein the
predetermined number of transmission signal sequences is the
minimum number of transmission signal sequences.
12. The base station apparatus according to claim 10, wherein the
predetermined number of transmission signal sequences is the
maximum number of transmission signal sequences.
13. A mobile station apparatus for periodically transmitting
transmission signal number-of-sequence information and reception
quality information calculated based on the transmission signal
number-of-sequence information to a base station apparatus,
comprising: a section that calculates the reception quality
information based on the predetermined number of transmission
signal sequences when the transmission signal number-of-sequence
information is not transmitted.
14. The mobile station apparatus according to claim 13, wherein the
predetermined number of transmission signal sequences is the
minimum number of transmission signal sequences.
15. The mobile station apparatus according to claim 13, wherein the
predetermined number of transmission signal sequences is the
maximum number of transmission signal sequences.
16. A mobile station apparatus for periodically transmitting
transmission signal number-of-sequence information and transmission
signal preprocessing information calculated based on the
transmission signal number-of-sequence information to a base
station apparatus, comprising: a section that calculates the
transmission signal preprocessing information based on the
predetermined number of transmission signal sequences when the
transmission signal number-of-sequence information is not
transmitted.
17. The mobile station apparatus according to claim 16, wherein the
predetermined number of transmission signal sequences is the
minimum number of transmission signal sequences.
18. The mobile station apparatus according to claim 16, wherein the
predetermined number of transmission signal sequences is the
maximum number of transmission signal sequences.
Description
TECHNICAL FIELD
[0001] The present invention relates to techniques where a mobile
station apparatus and base station apparatus perform radio
communications using all or a part of a plurality of antennas.
BACKGROUND ART
[0002] 3GPP (3rd Generation Partnership Project) is a project for
discussing and preparing specifications of cellular telephone
systems based on networks of evolved W-CDMA (Wideband-Code Division
Multiple Access) and GSM (Global System for Mobile Communications).
In 3GPP, the W-CDMA system has been standardized as the
3rd-generation cellular mobile communication system, and its
service is started sequentially. Further, HSDPA (High-Speed
Downlink Packet Access) with further increased communication rates
has also been standardized, and its service is started. 3GPP is
discussing evolution of the 3rd-generation radio access technique
(Evolved Universal Terrestrial Radio Access: hereinafter, referred
to as "E-UTRA").
[0003] As a downlink communication system in E-UTRA, proposed is an
OFDMA (Orthogonal Frequency Division Multiple Access) system for
multiplexing users using mutually orthogonal subcarriers. Further,
in the OFDMA system are applied techniques such as an adaptive
modulation/demodulation-error correcting scheme (AMCS: Adaptive
Modulation and Coding Scheme) based on adaptive radio link control
such as channel coding, etc.
[0004] AMCS is a scheme for switching radio transmission parameters
such as a coding rate of error correction, the level of data
modulation, etc. corresponding to propagation path conditions of
each mobile station apparatus so as to efficiently perform
high-speed packet data transmission. For example, data modulation
is switched to a multilevel modulation scheme with higher
modulation efficiency such 16QAM (Quadrature Amplitude Modulation),
64QAM, etc. from QPSK (Quadrature Phase Shift Keying) as the
propagation path conditions are better, and it is thereby possible
to increase maximum throughput in the mobile communication
system.
[0005] In OFDMA, it is possible to physically divide the
communicable region in the frequency domain corresponding to
subcarriers and time domain. A combination of some divided regions
is referred to as a resource block, one or more resource blocks are
allocated to each mobile station apparatus, and communications are
performed while multiplexing a plurality of mobile station
apparatuses.
[0006] In order that the base station apparatus and each mobile
station apparatus perform communications with optimal quality and
rate in response to the request, required is resource block
allocation and transmission scheme determination with consideration
given to the reception quality in each subcarrier in the mobile
station apparatus. Since the base station apparatus determines the
transmission scheme and scheduling, and only the mobile station
apparatus knows downlink propagation path conditions in Frequency
Division Duplex, to achieve the request, each mobile station
apparatus is required to give feedback of reception quality
(corresponding to MCS (Modulation-Error correcting coding scheme)
receivable in the mobile station) to base station apparatus. The
reception quality of each mobile station apparatus is fed back to
the base station apparatus by using CQI (Channel Quality
Indicator).
[0007] Further, to increase the communication path capacity in
E-UTRA, the use of transmission diversity has been proposed such as
SM (Space Multiplexing) technique using MIMO (Multiple Input
Multiple Output), SFBC (Space-Frequency Block Code) and the like.
By using MIMO, it is possible to form a plurality of propagation
paths as a space due to the effect of multipath, and multiplex a
plurality of pieces of information to transmit. On the reception
side, it is possible to combine power of a plurality of
transmission antennas to obtain the reception gain. Herein, these
techniques are collectively referred to as MIMO. In E-UTRA, it is
assumed to use SM by MIMO and transmission diversity on downlink,
and the scheme to perform communications is determined in
consideration of propagation path conditions between the base
station apparatus and mobile station apparatus.
[0008] In using MIMO-SM, to facilitate separation processing of a
plurality of space multiplexed sequences transmitted from antennas,
it is considered that the base station apparatus beforehand
performs preprocessing on transmission signal sequences. The
information of the transmission signal preprocessing cannot be
calculated in the base station apparatus, and each mobile station
apparatus needs to transmit the transmission signal preprocessing
information to the base station apparatus as feedback in MIMO-SM
communication.
[0009] Further, in MIMO-SM, the information of the number of
spatially multiplexed signal sequences is also dependent on the
propagation path between the mobile station apparatus and base
station apparatus, and is calculated in the mobile station
apparatus based on a reference signal transmitted from the base
station apparatus. In other words, each mobile station apparatus
needs to give feedback of this information to the base station
apparatus as well as the above-mentioned feedback information.
[0010] As described above, to achieve MIMO-SM communication, each
mobile station apparatus is required to transmit three kinds of
information i.e. the reception quality information, transmission
signal preprocessing information, and transmission signal
number-of-sequence information as feedback for the communication
path with the base station apparatus. The number of bits, format
and transmission frequency required to give each feedback are
different from one another, and are varied in a respective period
corresponding to propagation path conditions and conditions of the
mobile station apparatus.
[0011] More specifically, time variations are more moderate in the
optimal number of sequences of transmission signals than in the
transmission signal preprocessing information. When scheduling is
performed to always concurrently transmit the optimal number of
sequences of transmission signals and the transmission signal
preprocessing information, and feedback is performed in accordance
with the transmission period of the transmission signal
preprocessing information, the number of sequences of transmission
signals that is not varied undergoes feedback many times, and as a
result, overhead arises in uplink resources. Meanwhile, when
feedback is performed in accordance with the transmission period of
the number of sequences of transmission signals, information of the
transmission signal preprocessing information is insufficient in
the base station apparatus. As a result, MIMO communication is
performed by the preprocessing that is not suitable for the
transmission signal, and system throughput decreases.
[0012] Further, the information amounts of the reception quality
information and transmission signal preprocessing information are
varied with the number of transmission signal sequences. More
specifically, when different modulation schemes are applied for
each transmission signal sequence, the reception quality
information is required corresponding to the number of sequences.
Further, the transmission signal preprocessing information is
information represented by a matrix corresponding to the number of
transmission signal sequences and the number of transmission
antennas, and the number of required bits varies according to the
number of transmission signal sequences. From such a feature, it is
effective to transmit the number of transmission signal sequences
fast among the above-mentioned feedback information, and to
subsequently transmit the reception quality information and
transmission signal preprocessing information corresponding to the
reception quality information.
[0013] FIG. 11 contains a timing chart and sequence chart showing
the flow of processing between the base station apparatus and
mobile station apparatus in the conventional mobile communication
system. An example as shown in FIG. 11 is to implement a mechanism
as described in Non-patent Document to periodically transmit the
reception quality information, transmission signal preprocessing
information and the number of transmission signal sequences, is an
example of transmitting each kind of feedback information on a
periodically assigned uplink control channel (PUCCH: Physical
Uplink Control Channel), and describes feedback of from subframes 1
to 16.
[0014] Herein, to simplify, omitted are downlink signals, uplink
data signals, and feedback information such as ACK/NACK (Positive
Acknowledgement/Negative Acknowledgement) transmitted to the base
station apparatus from the mobile station apparatus, and the like.
In this example, resources of the uplink control channel are
allocated before subframe 1, and starting from subframe 1,
resources are allocated every three subframes (710). For the
reception quality information, transmission signal preprocessing
information and the number of transmission signal sequences
transmitted using the resources, their transmission timings are
shown in "711".
[0015] The base station apparatus notifies the mobile station
apparatus of information about the number of times once which the
number of transmission signal sequences is transmitted in the
resources, and in this example, it is set that such information is
transmitted once every four times in allocated resources. In other
words, the number of transmission signal sequences is periodically
transmitted in subframes 1 and 13, and it is assumed that the
numbers of transmission signal sequences are "3" and "4"
respectively (steps S701, S705). In remaining resources i.e. in
subframes 4, 7, 10 and 16, the reception quality information and
transmission signal preprocessing information is periodically
transmitted (steps S702, 703, S704, S706).
[0016] At this point, the reception quality information and
transmission signal preprocessing information is corresponding to
the last transmitted number of transmission signal sequences. In
other words, transmitted in subframes 4, 7 and 10 is the reception
quality information and transmission signal preprocessing
information corresponding to the number of transmission signal
sequences transmitted in the subframe 1 i.e. "3". Transmitted in a
subframe 16 is the reception quality information and transmission
signal preprocessing information corresponding to the number of
transmission signal sequences transmitted in a subframe 13 i.e.
"4".
[0017] Meanwhile, in E-UTRA, to suppress power consumption in the
mobile station apparatus, there is a technique of DRX
(Discontinuous Reception) that the power is turned on only for the
duration required by the mobile station apparatus to receive
signals. FIG. 12 is a diagram showing the outline of DRX control.
The mobile station apparatus repeats on-duration 802 and
opportunity for DRX 803 in a DRX cycle 801 (repetition cycle). When
the on-duration and DRX cycle are configured, the opportunity for
DRX is uniquely determined. The on-duration is a period of time
formed of one or more subframes defined to monitor PDCCH.
[0018] In the on-duration, the base station apparatus transmits
PDCCH to start uplink or downlink resource allocation. A mobile
station apparatus receiving PDCCH indicative of scheduling of
uplink or downlink initial transmission data (new data) in the
on-duration monitors PDCCH for a predetermined duration after the
on-duration (804). Further, for a duration having the possibility
of retransmission of uplink data or downlink data, the mobile
station apparatus monitors PDCCH irrespective of whether the
duration is in or out of the on-duration range (805). The duration
is referred to as Active Time during which the receiving section of
the mobile station apparatus is started and active to monitor PDCCH
(806).
[0019] The base station apparatus transmits data during the Active
Time of the mobile station apparatus. The base station apparatus
beforehand notifies the mobile station apparatus of the repetition
period and on-duration of the DRX cycle, and the mobile station
apparatus beforehand repeats power-on periodically based on the
information, while performing power-on corresponding to reception
conditions of PDCCH and data retransmission conditions (see
Non-patent Document 2).
[0020] Described next is an example of feedback as shown in
Non-patent Document 1 with the aforementioned DRX considered. FIG.
13 contains a timing chart and sequence chart showing the flow of
processing between the base station apparatus and mobile station
apparatus in the conventional mobile communication system. DRX is
shown in "912" in FIG. 13, and subframes 6 to 14 correspond to the
duration (herein, referred to as Non-active Time) except the Active
Time. As shown in "910", resources of each kind of feedback
information are allocated in subframes 1, 4, 7, 10, 13 and 16 as in
the example of FIG. 11, and the base station apparatus sets the
transmission signal number-of-sequence information to be
transmitted at a frequency of once every four times in the
allocated resources.
[0021] In other words, feedback is set to transmit the transmission
signal number-of-sequence information in subframes 1 and 13 and the
reception quality information and transmission signal preprocessing
information in subframes 4, 7, 10 and 16. In addition, in order to
halt feedback in accordance with the Non-active Time of DRX
notified from the base station apparatus, feedback from the mobile
station apparatus is given only in subframes 1, 14 and 16, and
transmitted as feedback is the transmission signal
number-of-sequence information (step S901), the reception quality
information and transmission signal preprocessing information (step
S902), and the reception quality information and transmission
signal preprocessing information (step S903).
[0022] However, transmission of the number of transmission signal
sequences in the subframe 13 corresponding to the subframe 16 (step
S903) is in the Non-active Time, and there is the problem that the
base station apparatus cannot know information that the reception
quality information and transmission signal preprocessing
information transmitted in the subframe 16 (step S903) corresponds
to which number of transmission signal sequences. Non-patent
Document 2 describes calculating and transmitting the reception
quality information and transmission signal preprocessing
information according to the last transmitted number of
transmission signal sequences, but when the opportunity for DRX is
large with respect to a rate of change in propagation path, the
possibility is high that the number of transmission signal
sequences is varied from the optimal number, and as a result, there
is the fear of reducing throughput characteristics.
[0023] Further, as in the case of not transmitting the number of
transmission signal sequences due to DRX, such a case arises that
the number of transmission signal sequences cannot be transmitted
because it is necessary to transmit another information with a
higher priority at timing scheduled to transmit the number of
transmission signal sequences.
[Non-patent Document 1] Summary of AH on AI 6.3.4 "UE Procedures
for downlink shared channel", 3GPP TSG-RAN WG1 Meeting #52,
R1-081137 [Non-patent Document 2] 3GPP TS 36.321 V8.0.0 (2007-12)
Technical Specification 3rd Generation Partnership Project;
Technical Specification Group Radio Access Network; Evolved
Universal Terrestrial Radio Access (E-UTRA) Medium Access Control
(MAC) protocol specification (Release 8)
DISCLOSURE OF INVENTION
Problems to be Solved by the Invention
[0024] However, in the aforementioned conventional techniques, for
example, when the transmission timing of the transmission signal
number-of-sequence information that is transmitted periodically
from the mobile station apparatus is made transmission disabled due
to a reason of Discontinuous Reception or the like, the
transmission signal number-of-sequence information is not
transmitted, and there is the problem that the base station
apparatus does not know which number of transmission signal
sequences is associated with the reception quality information that
is received immediately after the Discontinuous Reception.
[0025] In this case, it is considered that the mobile station
apparatus transmits the reception quality information according to
the transmission signal number-of-sequence information transmitted
immediately before Discontinuous Reception starts. However, for
example, when the moving speed of the mobile station apparatus is
fast, a change occurs in the propagation path conditions under
circumstances where the transmission signal number-of-sequence
information cannot be transmitted, the suitable number of
transmission signal sequences is also varied according to the
change, the reception quality information itself loses reliability,
and there is the problem that downlink reception characteristics
deteriorate.
[0026] The present invention was made in view of such
circumstances, and it is an object of the invention to provide a
mobile station apparatus, base station apparatus, communication
method and communication system for clarifying the number of
transmission signal sequences in association with reception quality
information that is generated immediately after the case where
periodical transmission of transmission signal number-of-sequence
quality indicative signal cannot be performed, and enabling the
base station apparatus to perform appropriate communication
resource allocation.
Means for Solving the Problem
[0027] (1) To attain the above-mentioned object, the present
invention took measures as described below. In other words, a
mobile communication system of the invention is a mobile
communication system in which a mobile station apparatus
periodically transmits transmission signal number-of-sequence
information and reception quality information calculated based on
the transmission signal number-of-sequence information to the base
station apparatus, and is characterized in that the mobile station
apparatus calculates the reception quality information based on the
beforehand determined number of transmission signal sequences when
the transmission signal number-of-sequence information is not
transmitted to the base station apparatus, and that the base
station apparatus processes the reception quality information based
on the beforehand determined number of transmission signal
sequences when the transmission signal number-of-sequence
information is not transmitted.
[0028] (2) Further, in the mobile communication system of the
invention, it is a feature that the beforehand determined number of
transmission signal sequences is the minimum number of transmission
signal sequences.
[0029] (3) Furthermore, in the mobile communication system of the
invention, it is another feature that the beforehand determined
number of transmission signal sequences is the maximum number of
transmission signal sequences.
[0030] (4) Further, a mobile communication system of the invention
is a mobile communication system in which a mobile station
apparatus periodically transmits transmission signal
number-of-sequence information and transmission signal
preprocessing information calculated based on the transmission
signal number-of-sequence information to a base station apparatus,
and is characterized in that the mobile station apparatus
calculates the transmission signal preprocessing information based
on the beforehand determined number of transmission signal
sequences when the transmission signal number-of-sequence
information is not transmitted to the base station apparatus, and
that the base station apparatus processes the transmission signal
preprocessing information based on the beforehand determined number
of transmission signal sequences when the transmission signal
number-of-sequence information is not transmitted.
[0031] (5) Furthermore, in the mobile communication system of the
invention, it is a feature that the beforehand determined number of
transmission signal sequences is the minimum number of transmission
signal sequences.
[0032] (6) Still furthermore, in the mobile communication system of
the invention, it is another feature that the beforehand determined
number of transmission signal sequences is the maximum number of
transmission signal sequences.
[0033] (7) Further, a base station apparatus of the invention is a
base station apparatus that periodically receives transmission
signal number-of-sequence information and reception quality
information that is calculated in a mobile station apparatus based
on the transmission signal number-of-sequence information from the
mobile station apparatus, and is characterized by having means for
processing the reception quality information based on the
beforehand determined number of transmission signal sequences when
the transmission signal number-of-sequence information is not
transmitted.
[0034] (8) Furthermore, in the base station apparatus of the
invention, it is a feature that the beforehand determined number of
transmission signal sequences is the minimum number of transmission
signal sequences.
[0035] (9) Still furthermore, in the base station apparatus of the
invention, it is another feature that the beforehand determined
number of transmission signal sequences is the maximum number of
transmission signal sequences.
[0036] (10) Further, a base station apparatus of the invention is a
base station apparatus that periodically receives transmission
signal number-of-sequence information and transmission signal
preprocessing information that is calculated in a mobile station
apparatus based on the transmission signal number-of-sequence
information from the mobile station apparatus, and is characterized
by having means for processing the transmission signal
preprocessing information based on the beforehand determined number
of transmission signal sequences when the transmission signal
number-of-sequence information is not transmitted.
[0037] (11) Furthermore, in the base station apparatus of the
invention, it is a feature that the beforehand determined number of
transmission signal sequences is the minimum number of transmission
signal sequences.
[0038] (12) Still furthermore, in the base station apparatus of the
invention, it is another feature that the beforehand determined
number of transmission signal sequences is the maximum number of
transmission signal sequences.
[0039] (13) Further, a mobile station apparatus of the invention is
a mobile station apparatus that periodically transmits transmission
signal number-of-sequence information and reception quality
information calculated based on the transmission signal
number-of-sequence information to a base station apparatus, and is
characterized by having means for calculating the reception quality
information based on the beforehand determined number of
transmission signal sequences when the transmission signal
number-of-sequence information is not transmitted.
[0040] (14) Furthermore, in the mobile station apparatus of the
invention, it is a feature that the beforehand determined number of
transmission signal sequences is the minimum number of transmission
signal sequences.
[0041] (15) Still furthermore, in the mobile station apparatus of
the invention, it is another feature that the beforehand determined
number of transmission signal sequences is the maximum number of
transmission signal sequences.
[0042] (16) Further, a mobile station apparatus of the invention is
a mobile station apparatus that periodically transmits transmission
signal number-of-sequence information and transmission signal
preprocessing information calculated based on the transmission
signal number-of-sequence information to a base station apparatus,
and is characterized by having means for calculating the
transmission signal preprocessing information based on the
beforehand determined number of transmission signal sequences when
the transmission signal number-of-sequence information is not
transmitted.
[0043] (17) Furthermore, in the mobile station apparatus of the
invention, it is a feature that the beforehand determined number of
transmission signal sequences is the minimum number of transmission
signal sequences.
[0044] (18) Still furthermore, in the mobile station apparatus of
the invention, it is another feature that the beforehand determined
number of transmission signal sequences is the maximum number of
transmission signal sequences.
ADVANTAGEOUS EFFECT OF THE INVENTION
[0045] According to the invention, when the transmission signal
number-of-sequence information is not transmitted with
communication resources periodically allocated by the base station
apparatus so as to transmit the transmission signal
number-of-sequence information, the transmission signal
number-of-sequence information is transmitted to the base station
apparatus with communication resources enabling the feedback
information to be transmitted allocated by the base station
apparatus subsequently to the communication resources. Therefore,
for example, even when the mobile station apparatus cannot transmit
feedback of the transmission signal number-of-sequence information
to the base station apparatus because a subframe that is the
transmission timing of the transmission signal number-of-sequence
information is in a period of Non-active Time of DRX, the mobile
station apparatus can give feedback in a subframe with uplink
control channel resource allocation subsequent to the end of the
Non-active Time of DRX. By this means, the base station apparatus
is able to know the correct transmission signal number-of-sequence
information after the end of the Non-active Time of DRX, and is
able to perform appropriate downlink communication resource
allocation based on the subsequently transmitted reception quality
information and transmission signal preprocessing information.
BRIEF DESCRIPTION OF DRAWINGS
[0046] FIG. 1 is a block diagram showing a configuration example of
a base station apparatus according to Embodiments of the
invention;
[0047] FIG. 2 is a block diagram showing a configuration example of
a mobile station apparatus according to Embodiments of the
invention;
[0048] FIG. 3 is a diagram showing a timing chart to explain the
flow of processing between the base station apparatus and mobile
station apparatus in a mobile communication system according to
Embodiment 1;
[0049] FIG. 4 is a sequence chart between the base station
apparatus and mobile station apparatus in the mobile communication
system according to Embodiment 1;
[0050] FIG. 5 is a diagram showing a timing chart to explain the
flow of processing between the base station apparatus and mobile
station apparatus in a mobile communication system according to
Embodiment 2;
[0051] FIG. 6 is a sequence chart between the base station
apparatus and mobile station apparatus in the mobile communication
system according to Embodiment 2;
[0052] FIG. 7 is a diagram showing a timing chart to explain the
flow of processing between the base station apparatus and mobile
station apparatus in a mobile communication system according to
Embodiment 3;
[0053] FIG. 8 is a sequence chart between the base station
apparatus and mobile station apparatus in the mobile communication
system according to Embodiment 3;
[0054] FIG. 9 is a diagram showing a timing chart to explain the
flow of processing between the base station apparatus and mobile
station apparatus in a mobile communication system according to
Embodiment 4;
[0055] FIG. 10 is a sequence chart between the base station
apparatus and mobile station apparatus in the mobile communication
system according to Embodiment 4;
[0056] FIG. 11 contains a timing chart and sequence chart showing
the flow of processing between a base station apparatus and mobile
station apparatus in a conventional mobile communication
system;
[0057] FIG. 12 is a diagram showing the outline of DRX control;
and
[0058] FIG. 13 contains another timing chart and sequence chart
showing the flow of processing between the base station apparatus
and mobile station apparatus in the conventional mobile
communication system.
DESCRIPTION OF SYMBOLS
[0059] 1 Data control section [0060] 3 Modulation coding section
[0061] 4 Transmission signal preprocessing section [0062] 5 Mapping
section [0063] 7 Inverse Fast Fourier Transform (IFFT) section
[0064] 11 Radio transmission section [0065] 12 Antenna [0066] 15
Radio reception section [0067] 17 Fast Fourier Transform (FFT)
section [0068] 21 Inverse Discrete Fourier Transform (IDFT) section
[0069] 22 Demodulation decoding section [0070] 23 Data extraction
section [0071] 25 Scheduler section [0072] 27 Transmission
information control section [0073] 31 Modulation code control
section [0074] 33 Frequency selection scheduler section [0075] 35
Transmission signal number-of-sequence information control section
[0076] 36 Transmission signal preprocessing information control
section [0077] 41 Data control section [0078] 43 Modulation coding
section [0079] 44 Discrete Fourier Transform (DFT) section [0080]
45 Mapping section [0081] 47 Inverse Fast Fourier Transform (IFFT)
section [0082] 51 Radio transmission section [0083] 53 Radio
reception section [0084] 55 Fast Fourier Transform (FFT) section
[0085] 57 Demodulation decoding section [0086] 61 Data extraction
section [0087] 63 Antenna [0088] 65 Feedback information control
section [0089] 67 Reception quality information generating section
[0090] 68 Transmission signal preprocessing information generating
section [0091] 69 Transmission signal number-of-sequence
information generating section [0092] 71 Reception quality
measuring section
BEST MODE FOR CARRYING OUT THE INVENTION
[0093] Embodiments of the invention will specifically be described
below with reference to drawings. In addition, in the following
description, the invention is embodied using a mobile communication
system, but is not limited thereto, and is achieved as a mobile
communication method.
Embodiment 1
[0094] A mobile communication system according to Embodiment 1 of
the invention is comprised of base station apparatuses and mobile
station apparatuses. FIGS. 1 and 2 are block diagrams showing
configuration examples of the base station apparatus and the mobile
station apparatus according to this Embodiment, respectively. As
shown in FIG. 1, the base station apparatus is provided with a data
control section 1, modulation coding section 3, transmission signal
preprocessing section 4, mapping section 5, Inverse Fast Fourier
Transform (IFFT) section 7, radio transmission section 11, radio
reception section 15, Fast Fourier Transform (FFT) section 17,
Inverse Discrete Fourier Transform (IDFT) section 21, demodulation
decoding section 22, data extraction section 23, transmission
information control section 27, and antenna 12.
[0095] The transmission information control section 27 includes a
scheduler section 25, modulation code control section 31, frequency
selection scheduler section 33, transmission signal
number-of-sequence information control section 35, and transmission
signal preprocessing information control section 36. The antenna 12
has the number of antennas required for MIMO-SDM communication.
[0096] The data control section 1 receives transmission data and
control data to transmit to each mobile station apparatus, and each
data is sequentially transmitted to the mobile station apparatus
according to directions from the transmission information control
section 27. When MIMO-SDM is applied to output data, the data is
divided into a plurality of transmission sequences according to
information of the transmission signal number-of-sequence
information control section 35.
[0097] The modulation coding section 3 performs modulation
processing and error correcting coding processing on a signal input
from the data control section 1, based on a modulation scheme and
coding rate by the transmission information control section 27, and
outputs the resultant signal to the transmission signal
preprocessing section 4. The transmission signal preprocessing
section 4 processes the signal input from the modulation coding
section 3 based on control information input from the transmission
information control section 27, and outputs the resultant signal to
the mapping section 5.
[0098] The mapping section 5 performs mapping of data output from
the modulation coding section 3 on each subcarrier based on
frequency selection scheduling information input from the
transmission information control section 27, and outputs the
resultant signal to the Inverse Fast Fourier Transform section 7.
The Inverse Fast Fourier Transform section 7 performs processing of
Inverse Fast Fourier Transform on the data output from the mapping
section 5 to transform into a time-series baseband digital signal,
and outputs the resultant signal to the radio transmission section
11.
[0099] The output signal from the Inverse Fast Fourier Transform
section 7 undergoes digital/analog conversion in the radio
transmission section 11, is up-converted into a signal with a
frequency suitable for transmission, and transmitted to each mobile
station apparatus via the antenna 12.
[0100] The scheduler section 25 performs downlink scheduling and
uplink scheduling based on control information such as a resource
area usable for each mobile station apparatus, intermittent
transmission/reception cycle, format of a transmission data
channel, buffer status and the like, while performing control of
varying the number of transmission signal sequences. The modulation
code control section 31 determines a modulation scheme and coding
rate applied to each data based on reception quality information
transmitted from the mobile station apparatus.
[0101] The frequency selection scheduler section 33 performs
processing of frequency selection scheduling applied to each data,
based on the feedback information transmitted from the mobile
station apparatus. The transmission signal number-of-sequence
information control section 35 determines the number of sequences
of transmission signals, based on the transmission signal
number-of-sequence information transmitted from the mobile station
apparatus, traffic status of the base station apparatus and the
like. The transmission signal preprocessing information control
section 36 determines preprocessing to apply to the transmission
data based on the transmission signal preprocessing information
transmitted from the mobile station apparatus.
[0102] The transmission information control section 27 controls
operations of the scheduler section 25, modulation code control
section 31, frequency selection scheduler section 33, transmission
signal number-of-sequence information control section 35,
transmission signal preprocessing information control section 36,
and transmission information control section 27, using control
information input from the higher layer and control information
input from the data extraction section 23. The section 27 manages
the output information of each section to output control
information required for operations of the data control section 1,
modulation coding section 3, transmission signal preprocessing
section 4 and mapping section 5.
[0103] The radio reception section 15 performs analog/digital
conversion on a signal received in the antenna 12 to down-covert
into a baseband signal, and outputs the resultant signal to the
Fast Fourier Transform (FFT) section 17. The Fast Fourier Transform
(FFT) section 17 performs Fourier transform on the reception signal
on a unit processing time basis to output to the Inverse Discrete
Fourier Transform section 21. The Inverse Discrete Fourier
Transform section 21 divides the input signal into bands assigned
to respective mobile station apparatuses to perform Inverse Fourier
transform processing, and outputs a reproduced SC-FDMA signal to
the demodulation decoding section 22.
[0104] The demodulation decoding section 22 performs demodulation
and decoding on the input signal for each mobile station apparatus
to output to the data extraction section 23. The data extraction
section 23 divides the signal input from the demodulation decoding
section 22 into information required for control information
generation in the transmission information control section 27,
reception data, and control data required for the higher layer to
output.
[0105] Meanwhile, as shown in FIG. 2, the mobile station apparatus
is provided with a data control section 41, modulation coding
section 43, Discrete Fourier Transform (DFT) section 44, mapping
section 45, Inverse Fast Fourier Transform (IFFT) section 47, radio
transmission section 51, radio reception section 53, Fast Fourier
Transform (FFT) section 55, demodulation decoding section 57, data
extraction section 61, and antenna 63. A feedback information
control section 65 has a reception quality information generating
section 67, reception quality measuring section 71, transmission
signal preprocessing information generating section 68, and
transmission signal number-of-sequence information generating
section 69. The antenna 63 is provided with the number of antennas
required for MIMO-SDM communication.
[0106] The data control section 41 receives transmission data,
control data and feedback information output from the feedback
information control section 65 each to transmit to the base station
apparatus, and each data is sequentially transmitted to the base
station apparatus.
[0107] The modulation coding section 43 performs modulation
processing and error correcting coding processing on the signal
input from the data control section 41, and outputs each data to
the Discrete Fourier Transform section 44. The Discrete Fourier
Transform section 44 performs Fourier transform processing on the
signal input from the modulation coding section 43, and generates a
signal to perform SC-FDMA to output to the mapping section 45. The
mapping section 45 performs mapping of the data input from the
Discrete Fourier Transform section 44 on subcarriers assigned by
the base station apparatus to output to the Inverse Fast Fourier
Transform section 47.
[0108] The Inverse Fast Fourier Transform section 47 performs
processing of Inverse Fast Fourier Transform on a symbol sequence
input from the mapping section 45 to transform into a time-series
baseband digital signal, and outputs the resultant signal to the
radio transmission section 51. The output signal from the Inverse
Fast Fourier Transform section 47 undergoes digital/analog
conversion in the radio transmission section 51, is up-converted
into a signal with a frequency suitable for transmission, and
transmitted to the base station apparatus via the antenna.
[0109] The reception quality measuring section 71 measures
reception quality of a signal received from the base station
apparatus. Based on the information measured by the reception
quality measuring section 71, the reception quality information
generating section 67 generates reception quality information to
transmit to the base station apparatus. The transmission signal
preprocessing information generating section 68 calculates
propagation path information using a signal received from the base
station apparatus, and generates information of preprocessing on a
transmission signal to be performed by the base station apparatus.
The transmission signal number-of-sequence information generating
section 68 calculates propagation path information using a signal
received from the base station apparatus, and calculates the number
of transmission sequences communicable with the base station
apparatus.
[0110] The feedback information control section 65 manages control
signals generated in the reception quality information generating
section 67, transmission signal preprocessing information
generating section 68, and transmission signal number-of-sequence
information generating section 69 to output to the data control
section 41. The feedback information managed in the feedback
information control section 65 is not limited to generation and
control of the signals described herein, and may include portions
to manage other kinds of feedback information.
[0111] FIG. 3 is a diagram showing a timing chart to explain the
flow of processing between the base station apparatus and mobile
station apparatus in a mobile communication system according to
Embodiment 1. FIG. 4 is a sequence chart between the base station
apparatus and mobile station apparatus in the mobile communication
system according to Embodiment 1. As shown in FIGS. 3 and 4, the
reception quality information, transmission signal preprocessing
information and transmission signal number-of-sequence information
is transmitted only in subframes subjected to uplink control
channel resource allocation that is performed by the base station
apparatus on the mobile station apparatus. Further, herein, it is
possible to concurrently transmit the reception quality information
and transmission signal preprocessing information, but transmission
signal number-of-sequence information is not transmitted
concurrently with the reception quality information and
transmission signal preprocessing information. In addition, in
FIGS. 3 and 4, as an example, the uplink control channel resource
allocation is made every three subframes, the transmission signal
number-of-sequence information is transmitted once every four times
the uplink control channel resource allocation is performed, and
the reception quality information and transmission signal
preprocessing information is periodically transmitted at the other
uplink control channel resource allocation times.
[0112] The operation of the mobile communication system according
to this Embodiment will be described below with reference to FIGS.
3 and 4. The base station apparatus is able to allocate uplink
control channel resources for the mobile station apparatus to
transmit the reception quality information, transmission signal
preprocessing information and transmission signal
number-of-sequence information permanently for the long term, for
example, using a radio resource control signal (RRC signaling).
First, the mobile station apparatus transmits the transmission
signal number-of-sequence information to the base station apparatus
as feedback in a subframe 1 first assigned uplink control channel
resources (step S41). Herein, the mobile station apparatus
transmits the transmission signal number-of-sequence information
from the subframe 1, and a subframe in which the mobile station
apparatus starts transmitting reception quality information,
transmission signal preprocessing information and transmission
signal number-of-sequence information can be set using an offset
value transmitted from the base station apparatus.
[0113] In a subframe 4 in which next uplink control channel
allocation is performed, the mobile station apparatus transmits to
the base station apparatus the reception quality information and
the transmission signal preprocessing information based on the
transmission signal number-of-sequence information (=3) transmitted
to the base station apparatus in the subframe 1 (step S42). Then,
Non-active Time of DRX starts from a subframe 6, and downlink data
transmission from the base station apparatus to mobile station
apparatus is suspended (step S43). In subframes 7 and 10, uplink
control channel resource allocation is performed, but the subframes
are in a period of Non-active Time of DRX, and feedback is not
given on the reception quality information and transmission signal
preprocessing information.
[0114] Next, a subframe 13 is timing of transmitting the
transmission signal number-of-sequence information as feedback, but
is still in the period of Non-active Time of DRX, and in this
subframe, feedback is not performed (step S43). The mobile station
apparatus performs feedback of transmission signal
number-of-sequence information (n=2) in a subframe 16 with next
uplink control channel resource allocation after the end of the
Non-active Time of DRX (step F44). Further, the subframe 16 is
originally the feedback timing of reception quality information and
transmission signal preprocessing information, but in this
subframe, since the transmission signal number-of-sequence
information is transmitted, feedback is not performed on the
reception quality information and transmission signal preprocessing
information. Then, in subframes 19 and 22 in which next uplink
control channel allocation is performed, the mobile station
apparatus transmits to the base station apparatus the reception
quality information and transmission signal preprocessing
information based on the transmission signal number-of-sequence
information (=2) transmitted in the subframe 16 (steps S45,
S46).
[0115] Next, in a subframe 25, the mobile station apparatus
transmits the transmission signal number-of-sequence information to
the base station apparatus as feedback (step S47). Then, in
subframes 28 and 31 in which next resource allocation for uplink
control channel is performed, the mobile station apparatus
transmits to the base station apparatus the reception quality
information and transmission signal preprocessing information based
on the transmission signal number-of-sequence information (=4)
transmitted to the base station apparatus in the subframe 25 (steps
S48, S49).
[0116] Thus, according to the mobile communication system according
to Embodiment 1 of the invention, even when a subframe that is the
transmission timing of the transmission signal number-of-sequence
information is in a period of Non-active Time of DRX and does not
enable feedback of the transmission signal number-of-sequence
information, since the transmission signal number-of-sequence
information is transmitted in a subframe with next uplink control
channel resource allocation after the end of the Non-active Time of
DRX, the base station apparatus is able to know the correct
transmission signal number-of-sequence information after the end of
the Non-active Time of DRX, and to perform appropriate downlink
communications based on the subsequently transmitted reception
quality information and transmission signal preprocessing
information.
[0117] In addition, in this Embodiment, in the subframe 16, the
transmission signal number-of-sequence information is transmitted,
instead of transmitting the reception quality information and the
transmission signal preprocessing information, but it is possible
to concurrently transmit all of the information. Further, it is
described that whether or not to perform feedback is determined in
the Active Time and Non-active Time of DRX, but whether or not to
perform feedback may be determined in on-duration of DRX and
opportunity for DRX.
Embodiment 2
[0118] A mobile communication system according to Embodiment 2 of
the invention will be described below with reference to drawings.
In the mobile communication system according to Embodiment 2 of the
invention, the mobile station apparatus sets the number of
transmission sequences at a predetermined value and transmits the
reception quality information and the transmission signal
preprocessing information corresponding to this value to the base
station apparatus as feedback until next feedback of transmission
signal number-of-sequence information is performed after Non-active
Time of DRX ends when feedback of the transmission signal
number-of-sequence information cannot be performed due to the
Non-active Time of DRX, and in this respect, the system according
to Embodiment 2 differs from the mobile communication system
according to Embodiment 1. In addition, the configurations of the
base station apparatus and mobile station apparatus are the same as
in FIGS. 1 and 2.
[0119] FIG. 5 is a diagram showing a timing chart to explain the
flow of processing between the base station apparatus and mobile
station apparatus in the mobile communication system according to
Embodiment 2. FIG. 6 is a sequence chart between the base station
apparatus and mobile station apparatus in the mobile communication
system according to Embodiment 2. As shown in FIGS. 5 and 6, also
in the mobile communication system according to this Embodiment,
the operations of subframes 1 to 13 (steps S61 to S63) are the same
as the operations in Embodiment 1, and descriptions thereof are
omitted.
[0120] Next, the mobile station apparatus performs the following
operation for a period during which Non-active Time of DRX ends and
next feedback of the transmission signal number-of-sequence
information (n=4) is performed in a subframe 25. In other words, in
subframes 16, 19 and 22 in which uplink control channel resource
allocation occurs, the mobile station apparatus transmits to the
base station apparatus the reception quality information and
transmission signal preprocessing information based on the
predetermined transmission signal number-of-sequence information
(steps S64, S65, S66). Herein, the predetermined transmission
signal number-of-sequence information is, for example, the number
of transmission signal sequences=1 (minimum value) that minimizes
the information amount of the feedback information from the mobile
station apparatus, or the number of transmission signal sequences=4
(maximum value) that enables the propagation path to be used most
efficiently (enables maximum throughput to be obtained) and the
like, and can be defined by specifications or the like in advance
between the base station apparatus and mobile station
apparatus.
[0121] Then, for the reception quality information and transmission
signal preprocessing information sent as feedback for a period
during which the Non-active Time of DRX ends and the mobile station
apparatus gives next feedback of the transmission signal
number-of-sequence information, the base station apparatus performs
the processing while regarding the transmission signal
number-of-sequence information as the predetermined value (for
example, the number of transmission signal sequences=1 (minimum
value) or the number of transmission signal sequences=4 (maximum
value)). Then, after receiving feedback of the transmission signal
number-of-sequence information (n=4) in the subframe 25 from the
mobile station apparatus (step S67), the base station apparatus
receives feedback of the reception quality information and
transmission signal preprocessing information based on the received
transmission signal number-of-sequence information (=4) in
subframes 28 and 31 (steps S68, S69).
[0122] In addition, FIGS. 5 and 6 describe setting a predetermined
value of transmission signal number-of-sequence information at "1"
as an example for a period during which Non-active Time of DRX ends
and next feedback of the transmission signal number-of-sequence
information is performed, but as described above, such a value can
be defined by specifications or the like in advance. Further, a
case occurs where the transmission signal preprocessing information
is not necessary such as a case that a value of transmission signal
number-of-sequence information corresponds to transmission
diversity of closed loop control. In this case, the mobile station
apparatus transmits only the reception quality information, and the
base station apparatus performs the processing by regarding the
reception quality information as being transmitted only.
[0123] Thus, according to the mobile communication system according
to Embodiment 2 of the invention, even when a subframe that is the
transmission timing of the transmission signal number-of-sequence
information is in a period of Non-active Time of DRX and does not
enable feedback of the transmission signal number-of-sequence
information, feedback of the reception quality information and the
transmission signal preprocessing information is given based on a
predetermined value of the transmission signal number-of-sequence
information until the mobile station apparatus transmits next
feedback of transmission signal number-of-sequence information
after the Non-active Time of DRX ends, and it is thereby possible
to prevent the occurrence of burst error due to communications
using the number of transmission signal sequences that is not
suitable for propagation path conditions.
Embodiment 3
[0124] A mobile communication system according to Embodiment 3 of
the invention will be described below with reference to drawings.
In the mobile communication system according to Embodiment 3 of the
invention, for a period during which Non-active Time of DRX ends
and next feedback of the transmission signal number-of-sequence
information is performed, the mobile station apparatus does not
transmit feedback of the reception quality information and the
transmission signal preprocessing information to the base station
apparatus, and for this period, the base station apparatus
transmits downlink data using the predetermined number of
transmission signal sequences. In this respect, Embodiment 3
differs from Embodiments 1 and 2. In addition, the configurations
of the base station apparatus and mobile station apparatus are the
same as in FIGS. 1 and 2.
[0125] FIG. 7 is a diagram showing a timing chart to explain the
flow of processing between the base station apparatus and mobile
station apparatus in the mobile communication system according to
Embodiment 3. FIG. 8 is a sequence chart between the base station
apparatus and mobile station apparatus in the mobile communication
system according to Embodiment 3. As shown in FIGS. 7 and 8, also
in the mobile communication system according to this Embodiment,
the operations of subframes 1 to 13 (steps S81 to S83) are the same
as the operations in Embodiment 1, and descriptions thereof are
omitted.
[0126] Next, the mobile station apparatus does not perform feedback
of the reception quality information and the transmission signal
preprocessing information for a period during which Non-active Time
of DRX ends and next feedback of the transmission signal
number-of-sequence information (n=4) is performed in a subframe 25
even in subframes (subframes 16, 19, 22) assigned uplink control
channel resources (step S84). The base station apparatus performs
transmission of downlink data in predetermined form for the period
during which Non-active Time of DRX ends and next feedback of the
transmission signal number-of-sequence information is
performed.
[0127] More specifically, in a subframe 23, the base station
apparatus transmits downlink signal allocation to the mobile
station apparatus on the control channel, and further transmits a
downlink signal in resources configured in the allocation. In this
subframe, the base station apparatus transmits the signal using the
predetermined number of transmission signal sequences. Herein, the
predetermined form is the number of transmission signal sequences=1
(minimum value) that minimizes the information amount of the
feedback information from the mobile station apparatus, the number
of transmission signal sequences=4 (maximum value) that enables the
propagation path to be used most efficiently (enables maximum
throughput to be obtained) and the like, and can be defined by
specifications or the like in advance between the base station
apparatus and mobile station apparatus.
[0128] Then, after receiving feedback of the transmission signal
number-of-sequence information (n=4) in the subframe 25 from the
mobile station apparatus (step S85), the base station apparatus
receives feedback of the reception quality information and
transmission signal preprocessing information based on the received
transmission signal number-of-sequence information (=4) in
subframes 28 and 31 (steps S86, S87). The base station apparatus
implements suitable downlink data transmission corresponding to the
transmission number-of-sequence information, reception quality
information and transmission signal preprocessing information.
[0129] Thus, according to the mobile communication system according
to Embodiment 3 of the invention, even when a subframe that is the
transmission timing of the transmission signal number-of-sequence
information is in a period of Non-active Time of DRX and does not
enable feedback of the transmission signal number-of-sequence
information, for a period during which the Non-active Time of DRX
ends and next feedback of the transmission signal
number-of-sequence information is performed, the mobile station
apparatus does not perform feedback of the reception quality
information and the transmission signal preprocessing information,
the base station apparatus transmits downlink data in predetermined
form, and it is thereby possible to reduce consumption of power to
transmit the feedback information that is not used.
Embodiment 4
[0130] A mobile communication system according to Embodiment 4 of
the invention will be described below with reference to drawings.
In the mobile communication system according to Embodiment 4 of the
invention, for a period during which Non-active Time of DRX ends
and next feedback of the transmission signal number-of-sequence
information is performed, even when the mobile station apparatus
performs feedback of the reception quality information and the
transmission signal preprocessing information, the base station
apparatus abandons (disables) the information and transmits
downlink data in predetermined form. In this respect, Embodiment 4
differs from Embodiments 1, 2 and 3. In addition, the
configurations of the base station apparatus and mobile station
apparatus are the same as in FIGS. 1 and 2.
[0131] FIG. 9 is a diagram showing a timing chart to explain the
flow of processing between the base station apparatus and mobile
station apparatus in the mobile communication system according to
Embodiment 4. FIG. 10 is a sequence chart between the base station
apparatus and mobile station apparatus in the mobile communication
system according to Embodiment 4. As shown in FIGS. 9 and 10, also
in the mobile communication system according to this Embodiment,
the operations of subframes 1 to 13 (steps S101 to 5103) are the
same as the operations in Embodiment 1, and descriptions thereof
are omitted.
[0132] Next, the mobile station apparatus performs the following
operation for a period during which Non-active Time of DRX ends and
next feedback of the transmission signal number-of-sequence
information is performed in a subframe 25. In other words, in
subframes (subframes 16, 19 and 22) in which uplink control channel
resource allocation is performed, the mobile station apparatus
transmits to the base station apparatus the reception quality
information and transmission signal preprocessing information based
on the last feedback (subframe 1) of transmission signal
number-of-sequence information (=3) (step S104). For the period
during which Non-active Time of DRX ends and next feedback of the
transmission signal number-of-sequence information is transmitted
from the mobile station apparatus, the base station apparatus
disables and abandons the reception quality information and
transmission signal preprocessing information fed back by the
mobile station apparatus, and performs transmission of downlink
data in predetermined form (step S104).
[0133] More specifically, in a subframe 23, the base station
apparatus transmits downlink signal allocation to the mobile
station apparatus on the control channel, and further transmits a
downlink signal in the resources configured in the allocation. In
this subframe, the base station apparatus abandons the received
number of transmission signal sequences, and transmits the signal
using the predetermined number of transmission signal sequences.
Herein, the predetermined form is the number of transmission signal
sequences=1 (minimum value) that minimizes the information amount
of the feedback information from the mobile station apparatus, the
number of transmission signal sequences=4 (maximum value) that
enables the propagation path to be used most efficiently (enables
maximum throughput to be obtained) and the like, and can be defined
by specifications or the like in advance between the base station
apparatus and mobile station apparatus.
[0134] Then, after receiving feedback of the transmission signal
number-of-sequence information (n=4) in the subframe 25 (step S105)
from the mobile station apparatus, the base station apparatus
receives feedback of the reception quality information and
transmission signal preprocessing information based on the received
transmission signal number-of-sequence information (=4) in
subframes 28 and 31 (steps S106, S107). The base station apparatus
performs suitable downlink data transmission according to the
transmission number-of-sequence information, reception quality
information and transmission signal preprocessing information.
[0135] Thus, according to the mobile communication system according
to Embodiment 4 of the invention, even when a subframe that is the
transmission timing of the transmission signal number-of-sequence
information is in a period of Non-active Time of DRX and does not
enable feedback of the transmission signal number-of-sequence
information, for a period during which the Non-active Time of DRX
ends and next feedback of the transmission signal
number-of-sequence information is performed, even in the case that
the mobile station apparatus performs feedback of the reception
quality information and the transmission signal preprocessing
information, the base station apparatus transmits downlink data in
predetermined form. It is thereby possible to prevent the
occurrence of burst error due to communications using the number of
transmission signal sequences that is not suitable for propagation
path conditions.
Embodiment 5
[0136] Embodiments 1 to 4 as described above show the case as an
example that DRX causes the reason of occurrence of the situation
that the mobile station apparatus cannot feedback the transmission
signal number-of-sequence information, but the reason is not
limited to DRX. Also when the situation occurs that the
transmission signal number-of-sequence information cannot be
transmitted due to reasons other than the DRX, the mobile station
apparatus and base station apparatus are able to apply Embodiments
1 to 4 as described above. For example, when such a situation
occurs that the mobile station apparatus cannot transmit the
transmission signal number-of-sequence information because of
transmitting a signal (hereinafter, referred to as a scheduling
request) for requesting resource allocation to the base station
apparatus, it is possible to apply Embodiments 1 to 4 as described
above. When such a situation occurs that the mobile station
apparatus cannot transmit the transmission signal
number-of-sequence information because of transmitting another
uplink control signal (for example, scheduling request) in a
subframe in which uplink control channel resource allocation is
performed to transmit the transmission signal number-of-sequence
information, it is possible to apply Embodiments 1 to 4 as
described above.
[0137] This example will be described using FIGS. 3 and 4 showing
Embodiment 1. In addition, configurations of the base station
apparatus and mobile station apparatus are the same as in FIGS. 1
and 2. As in Embodiment 1, first, the mobile station apparatus
transmits the transmission signal number-of-sequence information to
the base station apparatus as feedback in a subframe 1 first
assigned uplink control channel resources. Subsequently, in
subframes 4, 7 and 10 in which next uplink control channel
allocation is performed, the mobile station apparatus transmits to
the base station apparatus the reception quality information and
the transmission signal preprocessing information based on the
transmission signal number-of-sequence information (=3) transmitted
to the base station apparatus in the subframe 1. Embodiment 5 does
not consider DRX.
[0138] When such a situation occurs that the mobile station
apparatus cannot transmit the transmission signal
number-of-sequence information (=2) because of transmitting another
uplink control signal (for example, scheduling request) at the
timing of a subframe 13 in which the base station apparatus
performs uplink control channel resource allocation so as to
transmit the transmission signal number-of-sequence information,
the mobile station apparatus performs feedback of the transmission
signal number-of-sequence information (=2) in a subframe 16 in
which uplink control channel resource allocation is next performed.
As well as Embodiment 1, although the subframe 16 is originally the
timing of feedback of the reception quality information and
transmission signal preprocessing information, the mobile station
apparatus does not perform the feedback because of transmitting the
transmission signal number-of-sequence information. Then, in
subframes 19 and 22 in which next uplink control channel allocation
is performed, the mobile station apparatus transmits to the base
station apparatus the reception quality information and
transmission signal preprocessing information based on the
transmission signal number-of-sequence information (=2) that is the
feedback in the subframe 16.
[0139] Similarly, when such a situation occurs that the mobile
station apparatus cannot transmit the transmission signal
number-of-sequence information (for example, in the case of
transmitting another uplink control signal), as described in
Embodiment 2, the mobile station apparatus is capable of
transmitting feedback of the reception quality information and
transmission signal preprocessing information to the base station
apparatus while setting the number of transmission sequences at a
predetermined value until next feedback of the transmission signal
number-of-sequence information is performed in a subframe in which
uplink control channel resource allocation is performed.
[0140] Further, when such a situation occurs that the mobile
station apparatus cannot transmit the transmission signal
number-of-sequence information (for example, in the case of
transmitting another uplink control signal), as described in
Embodiment 3, the mobile station apparatus does not perform
feedback of the reception quality information and transmission
signal preprocessing information until next feedback of the
transmission signal number-of-sequence information is performed in
a subframe in which uplink control channel resource allocation is
performed, and the base station apparatus is capable of performing
downlink data transmission using the predetermined number of
transmission signal sequences.
[0141] Furthermore, when such a situation occurs that the mobile
station apparatus cannot transmit the transmission signal
number-of-sequence information (for example, in the case of
transmitting another uplink control signal), as described in
Embodiment 4, during a period until the mobile station apparatus
performs next feedback of the transmission signal
number-of-sequence information in a subframe in which uplink
control channel resource allocation is performed, even when the
mobile station apparatus transmits the reception quality
information and transmission signal preprocessing information as
feedback, the base station apparatus abandons (disables) the
information and is capable of transmitting downlink data in
predetermined form.
[0142] Thus, according to the mobile communication system according
to Embodiment 5 of the invention, when such a situation occurs that
the mobile station apparatus cannot transmit the transmission
signal number-of-sequence information due to the reason (for
example, transmission of another uplink control signal) except DRX,
the base station apparatus is capable of knowing the correct
transmission signal number-of-sequence information, and performing
appropriate downlink communications based on the subsequently
transmitted reception quality information and transmission signal
preprocessing information.
[0143] In aforementioned Embodiments 1 to 5, scheduling is
performed so as to transmit the reception quality information and
transmission signal preprocessing information at the same timing,
but it is possible to perform the similar processing also in the
case of performing scheduling so that the information is in
different subframes.
[0144] (A) A mobile station apparatus according to this Embodiment
is a mobile station apparatus having a plurality of antennas to
perform radio communications with a base station apparatus using
all or a part of the plurality of antennas, has a feedback
information generating section that generates feedback information
including reception quality information indicative of reception
quality, transmission signal preprocessing information used by the
base station apparatus in performing preprocessing on a
transmission signal, and transmission signal number-of-sequence
information indicative of multiplexed transmission signal
sequences, and a transmitting section that periodically transmits
the generated feedback information to the base station apparatus,
and is characterized in that when the transmitting section does not
transmit the transmission signal number-of-sequence information
with communication resources periodically allocated from the base
station apparatus so as to transmit the transmission signal
number-of-sequence information, the transmitting section transmits
the transmission signal number-of-sequence information to the base
station apparatus with communication resources enabling
transmission of the feedback information allocated from the base
station apparatus subsequently to the communication resources.
[0145] Thus, when the mobile station apparatus does not transmit
the transmission signal number-of-sequence information with
communication resources periodically allocated by the base station
apparatus so as to transmit the transmission signal
number-of-sequence information, the mobile station apparatus
transmits the transmission signal number-of-sequence information to
the base station apparatus with communication resources enabling
transmission of the feedback information allocated from the base
station apparatus subsequently to the communication resources.
Therefore, for example, even when the mobile station apparatus
cannot transmit feedback of the transmission signal
number-of-sequence information to the base station apparatus
because a subframe that is the transmission timing of transmission
signal number-of-sequence information is in a period of Non-active
Time of DRX, the mobile station apparatus is capable of performing
the feedback in a subframe with uplink control channel resource
allocation subsequent to the end of the Non-active Time of DRX. By
this means, the base station apparatus is capable of knowing the
correct transmission signal number-of-sequence information after
the end of the Non-active Time of DRX, and performing appropriate
downlink communication resource allocation based on the
subsequently transmitted reception quality information and
transmission signal preprocessing information.
[0146] (B) Further, a mobile station apparatus according to this
Embodiment is a mobile station apparatus having a plurality of
antennas to perform radio communications with a base station
apparatus using all or a part of the plurality of antennas, has a
feedback information generating section that generates feedback
information including reception quality information indicative of
reception quality, transmission signal preprocessing information
used by the base station apparatus in performing preprocessing on a
transmission signal, and transmission signal number-of-sequence
information indicative of multiplexed transmission signal
sequences, and a transmitting section that periodically transmits
the generated feedback information to the base station apparatus,
and is characterized in that when the transmitting section does not
transmit the transmission signal number-of-sequence information
with communication resources periodically allocated from the base
station apparatus so as to transmit the transmission signal
number-of-sequence information, the feedback information generating
section generates the reception quality information and
transmission signal preprocessing information corresponding to the
beforehand defined number of transmission signal sequences during a
period until communication resources periodically allocated from
the base station apparatus so as to transmit the transmission
signal number-of-sequence information subsequent to the
communication resources, and the transmitting section transmits at
least one of the transmission equality information and transmission
signal preprocessing information corresponding to the beforehand
defined number of transmission signal sequences to the base station
apparatus.
[0147] Thus, when the mobile station apparatus does not transmit
the transmission signal number-of-sequence information with
communication resources periodically allocated from the base
station apparatus so as to transmit the transmission signal
number-of-sequence information, the mobile station apparatus
transmits at least one of the transmission equality information and
transmission signal preprocessing information corresponding to the
beforehand defined number of transmission signal sequences to the
base station apparatus during a period until communication
resources periodically allocated from the base station apparatus so
as to transmit the transmission signal number-of-sequence
subsequent to the communication resources. Therefore, for example,
even when the mobile station apparatus cannot perform feedback of
the transmission signal number-of-sequence information because a
subframe that is the transmission timing of transmission signal
number-of-sequence information is in a period of Non-active Time of
DRX, the mobile station apparatus is capable of performing feedback
of the reception quality information and transmission preprocessing
information corresponding to a predetermined fixed value of the
transmission signal number-of-sequence information until next
feedback of subsequent transmission signal number-of-sequence
information from the mobile station apparatus after the end of the
Non-active Time of DRX. By this means, the base station apparatus
is capable of performing appropriate downlink communication
resource allocation.
[0148] (C) Further, a mobile station apparatus according to this
Embodiment is a mobile station apparatus having a plurality of
antennas to perform radio communications with a base station
apparatus using all or a part of the plurality of antennas, has a
feedback information generating section that generates feedback
information including reception quality information indicative of
reception quality, transmission signal preprocessing information
used by the base station apparatus in performing preprocessing on a
transmission signal, and transmission signal number-of-sequence
information indicative of multiplexed transmission signal
sequences, and a transmitting section that periodically transmits
the generated feedback information to the base station apparatus,
and is characterized in that when the transmitting section does not
transmit the transmission signal number-of-sequence information
with communication resources periodically allocated from the base
station apparatus so as to transmit the transmission signal
number-of-sequence information, the transmitting section halts
transmission of the feedback information for a period until
communication resources periodically allocated from the base
station apparatus so as to transmit the transmission signal
number-of-sequence information subsequent to the communication
resources.
[0149] Thus, when the mobile station apparatus does not transmit
the transmission signal number-of-sequence information with
communication resources periodically allocated from the base
station apparatus so as to transmit the transmission signal
number-of-sequence information, the mobile station apparatus halts
transmission of the feedback information during a period until
communication resources periodically allocated from the base
station apparatus so as to transmit the transmission signal
number-of-sequence information subsequent to the communication
resources. Therefore, even when the mobile station apparatus cannot
perform feedback of the transmission signal number-of-sequence
information because a subframe that is the transmission timing of
transmission signal number-of-sequence information is in a period
of Non-active Time of DRX, the mobile station apparatus does not
perform feedback of the reception quality information and
transmission signal preprocessing information for a period during
which the Non-active Time of DRX ends and next feedback is
performed on the transmission signal number-of-sequence
information, and the base station apparatus is capable of
performing downlink communication resource allocation in
predetermined form. By this means, downlink communications can be
performed as normally as possible.
[0150] (D) Further, a base station apparatus according to this
Embodiment is a base station apparatus having a plurality of
antennas to perform radio communications with a mobile station
apparatus using all or a part of the plurality of antennas, has a
scheduler section that periodically allocates communication
resources to the mobile station apparatus in order for the mobile
station apparatus to transmit transmission signal
number-of-sequence information, and a transmission signal
number-of-sequence information control section that determines the
number of transmission signal sequences at least based on the
transmission signal number-of-sequence information transmitted from
the mobile station apparatus, and is characterized in that when the
mobile station apparatus does not transmit the transmission signal
number-of-sequence information with the communication resources,
the transmission signal number-of-sequence information control
section determines the number of transmission signal sequences
based on information transmitted with communication resources
enabling transmission of the feedback information allocated
subsequently to the communication resources.
[0151] Thus, when the mobile station apparatus does not transmit
the transmission signal number-of-sequence information with the
communication resources, since the number of transmission signal
sequences is determined based on information transmitted with
communication resources enabling transmission of the feedback
information allocated subsequently to the communication resources.
Therefore, for example, even when the mobile station apparatus
cannot transmit feedback of the transmission signal
number-of-sequence information to the base station apparatus
because a subframe that is the transmission timing of transmission
signal number-of-sequence information is in a period of Non-active
Time of DRX, the feedback can be given in a subframe in which
uplink control channel resource allocation is performed
subsequently to the end of the Non-active Time of DRX. By this
means, the base station apparatus is capable of knowing the correct
transmission signal number-of-sequence information after the end of
the Non-active Time of DRX, and performing appropriate downlink
communication resource allocation based on the subsequently
transmitted reception quality information and transmission signal
preprocessing information.
[0152] (E) Further, a base station apparatus according to this
embodiment is a base station apparatus having a plurality of
antennas to perform radio communications with a mobile station
apparatus using all or a part of the plurality of antennas, has a
scheduler section that periodically allocates communication
resources to the mobile station apparatus in order for the mobile
station apparatus to transmit transmission signal
number-of-sequence information, and a transmission signal
number-of-sequence information control section that determines the
number of transmission signal sequences at least based on the
transmission signal number-of-sequence information transmitted from
the mobile station apparatus, and is characterized in that when the
mobile station apparatus does not transmit the transmission signal
number-of-sequence information with the communication resources,
the transmission signal number-of-sequence information control
section uses the beforehand defined number of transmission signal
sequences as the number of transmission signal sequences until
communication resources periodically allocated to transmit the
transmission signal number-of-sequence information subsequent to
the communication resources.
[0153] Thus, when the mobile station apparatus does not transmit
the transmission signal number-of-sequence information with the
communication resources, the beforehand defined number of
transmission signal sequences is used as the number of transmission
signal sequences until communication resources periodically
allocated to transmit the transmission signal number-of-sequence
information subsequent to the communication resources. Therefore,
for example, even when the mobile station apparatus cannot perform
feedback of the transmission signal number-of-sequence information
because a subframe that is the transmission timing of transmission
signal number-of-sequence information is in a period of Non-active
Time of DRX, it is possible to use the reception quality
information and transmission preprocessing information
corresponding to a predetermined fixed value of the transmission
signal number-of-sequence information until feedback of subsequent
transmission signal number-of-sequence information is given from
the mobile station apparatus after the end of the Non-active Time
of DRX. By this means, the base station apparatus is capable of
performing appropriate downlink communication resource
allocation.
[0154] (F) Further, a base station apparatus according to this
Embodiment is a base station apparatus having a plurality of
antennas to perform radio communications with a mobile station
apparatus using all or a part of the plurality of antennas, has a
scheduler section that periodically allocates communication
resources to the mobile station apparatus in order for the mobile
station apparatus to transmit transmission signal
number-of-sequence information, and a transmission signal
number-of-sequence information control section that determines the
number of transmission signal sequences at least based on the
transmission signal number-of-sequence information transmitted from
the mobile station apparatus, and is characterized in that when the
mobile station apparatus does not transmit the transmission signal
number-of-sequence information with the communication resources,
the transmission signal number-of-sequence information control
section abandons feedback information transmitted from the mobile
station apparatus until communication resources periodically
allocated to transmit the transmission signal number-of-sequence
information subsequent to the communication resources.
[0155] Thus, when the mobile station apparatus does not transmit
the transmission signal number-of-sequence information with the
communication resources, feedback information transmitted from the
mobile station apparatus is abandoned for a period until
communication resources periodically allocated to transmit the
transmission signal number-of-sequence information subsequent to
the communication resources. Therefore, when the mobile station
apparatus cannot perform feedback of the transmission signal
number-of-sequence information because a subframe that is the
transmission timing of transmission signal number-of-sequence
information is in a period of Non-active Time of DRX, even in the
case that the mobile station apparatus performs feedback of the
reception quality information and transmission signal preprocessing
information for a period during which the Non-active Time of DRX
ends and next feedback is performed on the transmission signal
number-of-sequence information, the base station apparatus disables
the information and is capable of performing downlink communication
resource allocation in predetermined form. By this means, downlink
communications can be performed as normally as possible.
[0156] (G) Further, a communication method according to this
Embodiment is a communication method in which a mobile station
apparatus periodically transmits feedback information including
reception quality information indicative of reception quality,
transmission signal preprocessing information used in performing
preprocessing on a transmission signal, and transmission signal
number-of-sequence information indicative of multiplexed
transmission signal sequences to a base station apparatus, and the
base station apparatus receives the feedback information
periodically from the mobile station apparatus and allocates
communication resources to the mobile station apparatus based on
the received feedback information, and is characterized in that
when the mobile station apparatus does not transmit the
transmission signal number-of-sequence information with
communication resources periodically allocated from the base
station apparatus so as to transmit the transmission signal
number-of-sequence information, the mobile station apparatus
transmits the transmission signal number-of-sequence information to
the base station apparatus with communication resources enabling
transmission of the feedback information allocated from the base
station apparatus subsequently to the communication resources, and
that when the mobile station apparatus does not transmit the
transmission signal number-of-sequence information with
communication resources periodically allocated to transmit the
transmission signal number-of-sequence information, the base
station apparatus receives the transmission signal
number-of-sequence information transmitted with communication
resources enabling transmission of the feedback information
allocated subsequently to the communication resources, and
determines the number of transmission signal sequences.
[0157] Thus, when the mobile station apparatus does not transmit
the transmission signal number-of-sequence information with
communication resources periodically allocated from the base
station apparatus so as to transmit the transmission signal
number-of-sequence information, the mobile station apparatus
transmits the transmission signal number-of-sequence information to
the base station apparatus with communication resources enabling
transmission of the feedback information allocated from the base
station apparatus subsequently to the communication resources.
Therefore, for example, even when the mobile station apparatus
cannot transmit feedback of the transmission signal
number-of-sequence information to the base station apparatus
because a subframe that is the transmission timing of transmission
signal number-of-sequence information is in a period of Non-active
Time of DRX, the mobile station apparatus is capable of performing
the feedback in a subframe in which uplink control channel resource
allocation is performed subsequently to the end of the Non-active
Time of DRX. By this means, the base station apparatus is capable
of knowing the correct transmission signal number-of-sequence
information after the end of the Non-active Time of DRX, and
performing appropriate downlink communication resource allocation
based on the subsequently transmitted reception quality information
and transmission signal preprocessing information.
[0158] (H) Further, a communication system according to this
Embodiment is characterized by being comprised of the mobile
station apparatus as described in (A) and the base station
apparatus as described in (D), the mobile station apparatus as
described in (B) and the base station apparatus as described in
(E), or the mobile station apparatus as described in (C) and the
base station apparatus as described in (F).
[0159] According to this constitution, for example, after the end
of Non-active Time of DRX in the mobile station apparatus, the base
station apparatus is capable of knowing the correct transmission
signal number-of-sequence information, and performing appropriate
downlink communication resource allocation based on the
subsequently transmitted reception quality information and
transmission signal preprocessing information.
[0160] In the foregoing, each of the Embodiments of the invention
is described specifically with reference to drawings, but specific
constitutions are not limited to the above-mentioned Embodiments,
and designs and others in the scope without departing from the
subject matter of the invention are included in the scope of the
claims.
* * * * *